| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of longitudinal stripes and bellows at the time of temper rolling and to efficiently manufacture ultra thin steel sheets by making the outer layer part of a work roll of a sintered hard alloy and setting the thickness of the outer layer part to a specified thickness. SOLUTION: A steel sheet 3 after annealing is again rolled with a 1st stand 1 and temper rolling is executed with the 2nd stand. The draft at the 1st stand 1 is set so as to be 20% and, as the rolling conditions at the 2nd stand 2, the elongation percentage is set to a prescribed elongation percentage of <=1%. The elongation percentage is realized by adjusting the tension on the outlet side of the steel sheet matching to rolling load. It is preferable to adopt a sintered hard alloy (for example, WC-Co (20 wt.%), Young's modulus: 35,000 kgf/mm2) as the base stock for the work rolls 2a, 2b of the 2nd stand 2 and to set the thickness of the outer layer part to >=3% of the radius of the roll. A composite roll in which a sleeve made of the sintered hard alloy is fit may be used.
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